第五章 有机磷化合物作中间体

1、第五章 有机磷化合物作中间体的合成反应5.1 膦叶立德(Phosphonium ylid)膦叶立德是一种-碳负离子的内鏻盐R2CPR3RHCPPh3RHCPPh3PPh3RHCPPh3RH2CBaseP具有3d空轨道, C有2p轨道, P与C形成共轭体系Ph3PCRR1123R,R1为吸电子基团R,R1为烷基R,R1为芳香基5.1.1 膦叶立德的制备其中, 当R,R=COOR, COR, CN, 时, Base= KOH, NaOEt, K2CO3, ; 当R,R=烷基时, Base= n-BuLi, NaH, Ph3PRRXPh3PCHRRXBasePh3PCRR5.1.2 缩合反应(Wit

2、tig Reaction)R3PCR1R2OR3R4CCR1R2R3R3PR3O+CCR1R2R3R3PR3OCCR1R2R3R3+R3PO主要用于合成双取代烯烃, 反应的特点: 稳定的膦叶立德与醛反应,优先生成反式烯烃 不稳定的膦叶立德与醛反应,优先生成顺式烯烃1. 三取代烯烃的选择性较差VITAMIN D2HOC9H17OPh3PC9H17O3C9H17OHOOC9H17HOOPh3PCH2C9H17HOV itam in D2CHO+Ph3P2Ph3PCHCOOCH3+CHOOHCCH3OOCCOOCH3Ph3P+OCHOO茉莉酮 cis-jasmoneOPh3PCHCCH2BrO+OO

3、NaH/DMFOO+OCH3Ph3PCHCHCOR2RR1CH CH R2RR1CHO增加1个C原子的醛+NR2Ph3PCHOONR2O+C lP h3PC HRR OClCCHRR NaNH2REARRANGEMENTRCCRO+PPh3PPh3OOPPh35.1.3 Scoopy ReactionRHOPPh3CH3HR1OR1 = AlkylR1 = HCH3R1HOHRHCH3RCH2OH Z型BuLiPh3P=CHCH3+RCHOTHF-78deg CCHCH3Ph3PCHROR1CHOPPh3+OCHOTHP12BuLiHCHOOHCH2OTHP返幼激素juvenile hormo

4、ne 5.1.4 烃化反应一般的烃化反应：Ph3PCHR+RXPh3PCHRRXCHCHPPh3PPh3BrCH2BrCH2+PPh3PPh3Ph3PCH2CH2CH2CH2BrBrPhLiPh3PCH2CH2CH2CH2BrBrPh3PPhLiPh3PPh2CPh2CO5.1.5 酰化反应Ph3PCHR+R1COClPh3PCHRCOR1ClPh3P=CHRPh3P=CRCOR1+ Ph3PCHRCOR1Cl （用途广）Ph3P=CRCOR1R2CHOH2OR2CH=CRCOR1RCH2COR1RCCR15.2 膦酸酯 n5.2.1 Wittig-Horner Reactionn在反应中，R

5、CH2PO(OEt)2中，R是吸电子基团，如R=CN, COOR, COR等RCH2PO(OEt)2P(OEt)2ORCH2NaOAcR1R2OP(OEt)2ORCHP(OEt)2OCHRCR1R2OOP(OEt)2R1R2ROCHRR1R2特点：1 原料易得，价格便宜PCl3 +EtOHP(OEt)3RCH2XPCH2REtOEtOOEtXPOEtOOEtCH2R2. C产物易分离，副产物易溶于水3. 得到反式结构的烯烃4. 缺点: R必须是吸电子基团，不然就只形 成四员环化合物。OOOOCArOC5H11OOOOOCAr(EtO)2PCH2COC5H11ONaH，DME练习 完成下列反应式O+(EtO)2PCHNO?O?OO+BrCH2COCH=PPh3NaHDMF?Ph3P=CHCOCH3+CO